Standard Chess
1.d4 d6 is an offbeat yet reasonable weapon for Black, as the "queenless middlegame" after 2.c4 e5 3.dxe5 dxe5 4.Qxd8+ Kxd8 is considered to be entirely acceptable for the second player, (his king will find a comfy home on c7). The superior technical player will typically prevail in such queenless battles, but it's worth understanding why moves like 12.e4 and 17.a4 ought to be avoided!